This invention relates to a ceramic tile expansion engine housing including interlocking ceramic tiles which form an expandable ceramic housing, a pressurizable external metal housing which provides a support for the ceramic tiles, and means for thermally insulating the metal housing from the ceramic housing.
There has been much interest in the use of ceramic materials in internal combustion engines which would permit such engines to operate at much higher temperatures. It has, for example, been proposed to line combustion surfaces with high temperature ceramics. Typical suggestions of this nature may be found, for example, in Pennila U.S. Pat. No. 4,074,671 and Adams U.S. Pat. No. 4,774,926, which suggest the use of ceramic coatings on combustion chamber surfaces, as well as in Prewo et al. U.S. Pat. No. 4,341,826, Palm U.S. Pat. No. 4,530,341, Woods et al. U.S. Pat. No. 4,562,799, and Kawamura et al. U.S. Pat. No. 4,911,109 which suggest the use of ceramic inserts or liners, including monolithic liners, for use in such engines.
It has also been proposed to use ceramic materials in the development of a class of fuel-tolerant ceramic expansion engines such as Roots-type engines and Lysholm-type engines which utilize the expansion of hot gases to turn fluted rotors. Such engines, like internal combustion engines, operate best at elevated temperatures above the normal operating temperatures tolerated by either conventional metal parts or less conventional high temperature metal alloys.
While, as discussed above, it has been proposed to provide surfaces capable of withstanding higher temperatures by lining metal surface with ceramics, or by the use of ceramic monoliths such as cylinder liners, such approaches fail to take into account the degree of expansion which such ceramic parts will undergo as they heat up from room temperature up to the operating temperature, as well as the tremendous thermal mismatch which will occur when the ceramic parts are used as lining materials in combination with metal parts, with no provision for expansion or contraction.